Centerless grinding machine



NOV. 25, 1930. R SEWARlj 1,782,480

CENTERLESS GRINDING MACHINE Fi led Aug. 6, 1925 2 Sheets-Sheet 1 WITNESSES I INVENTOR h Ernest flfieurard 1/ -/1 NOV. 25, 19 30. s w 1,782,480

'CENTERLESS GRINDING MACHINE Filed Aug. 6, 1925 2 Sheets-Sheet 2 Jay 2 WITNESSES IINVENTOR 4 6 Ernest H. Seward 'tus, and more particularly to centerless grindmemes Nov. 25, 1930 UNITED STATES nitnnsr a. snwann, or nnrnorr,

PATENT OFFICE MICHIGAN, ASSIGNOR, BY MESNE ASSIGNMENTS, T0

GENTERLESS GRINDING MACHINE Application filed August 6, 1925. Serial No. 48,492.

This invention relates to grinding apparaing machines wherein the work of round section is supported between a grinding wheel and a work regulating wheel for grinding by the former while the latter rotates the work. More particularly the invention relates to machines of this latter type wherein the work regulating wheel is mounted for rotation below the grinding wheel, and supports as well as rotates the work during grinding action thereon by the grinding wheel.

A grinding machine, particularly, a centerless grinding machine wherein the work is supported between, and respectively ground and rotated by, a rotating, grinding wheel and work regulating wheel, must be rigidly constructed so as to avoid vibration of the work, or ofany part of the machine in contact with the work, during grinding. Heretofore, in order to secure the required rigid- ,ity, it has been common practice to mount.

the work regulating wheel spindle in bearings upon both sides of the wheel, and these bearings have been in turn fitted into the two arms of a yoke mouted on-a column or slide to be moved towards or away from the grind ing wheel. 1

In a grinding machine in which the regulating wheel is mounted beneath the grinding wheel, if bearings of the usual type are employed, there is a great possibility of water and grit getting into the bearings, and it is highly important that provision be made to insure the lower wheel being correctly positioned and kept in true alignment, that the bearings do not wear to such an extent to cause the wheel to get out of position, and that provision be made toprevent water and grit from getting into the bearings.

A work regulating wheel is generally and preferably constructed of an abrasive material. Its action upon the work t'o be ground is not an abrasive action, however, but merely an action controlling the rotation of the work during grinding The abrasive material permitsthe regulating wheel to get a secure grip or hold on the round work and thus dependably controls the rotation of the latter. It, is

often necessary, however, to replace the regwas then re-fitted and mounted ulating wheel by another wheel of different abrasive characteristics more suitable for the particular class of work being ground. Also, since the wheel must be truedto shape at times, it is necessary occasionally to replace a wheel which has become too small by a new one. I v

The above mentioned prior construction for mounting the work regulating wheel has been objectionable because the work regulating wheel couldnot be readily removed. When removing the wheel it has been necessary first to dismount the Wheel spindle from its bearings and then remove the wheel and secure another on the spindle. The spindle in its bearings. This latter operation often involved 7 re-scraping the bearings and required considerable time and the services of a highly skilled mechanic.

It is an object of the present invention to overcome difficulties such as those mentioned above and to provide an improved mounting for the work regulating wheel of a centerless grinding machine which will be of rigid construction and is so arranged that the operator may change the wheel readily as desired.

Another object of the invention is the provision of means for effectively sealing the bearing for the work regulating wheel from grinding liquid and dirt.

Another object of this invention is to provide a centerless grinding apparatus of the character pointed out above in which the regulating wheel is dependably mounted to permit its rapid and convenient removal or replacement While nevertheless the Wheel mounting is dependably adapted to resist thrusts lmposed thereon during the operation of the apparat s and so that high preoision of action may be consistently maintained.

Another object is to provide a cantilever mounting for an abrasive wheel that will be of simple, inexpensive and durable construction, of thoroughly dependable action, and well adapted to meet the varying conditions of hard practical use.

mounting for an abrasive wheel-that is capa- Another object is to provide a cantilever ble of being readily assembled, that will be of compact construction, and capable of positively and reliably supporting and driving)th'e abrasive wheel.

ther objects will be in art obvious or in part pointed out hereina er.-

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings in which is shown a preferred embodiment of my invention, and in which similar reference characters refer to similar parts throughout the several views,

Fig. 1 is a side elevation of a grinding machine embodying the invention;

Fig. 2 is an elevation on an enlarged scale of a portion of the machine as seen from the right-hand end of Figure 1, showing the mounting for the work. regulating wheel in section.

In Fig. .1 of the drawings I have illustrated a centerless grinding machine embodying the invention. A grinding wheel 5 is secured upon a spindle 6 mounted for rotation, preferably, at a relatively high speed,in suitable bearings in the upper righthand and substantially over-hanging portion of the base or frame 7 of the machine. pulley 8 is mounted upon a shaft 9-, which is rotatably supported near the bottom of the frame 7 and is rotated from any suitable source of power, to drive a belt 10 passing over a pulley 11 upon the grinding wheel spindle 6. The belt 10 is maintained properly tensioned by means of suitable idler pulleys 12 and 13 held in an adjustable bracket 14, which is pivotally mounted upon the base or frame 7 by means of a bolt 15 and locked in adjusted position by means of a bolt 16 passing through a slot 17 in the bracket 14.

A work regulating wheel 18 is held in operative relation with the grinding Wheel 5 upon-a suitable mounting (as will be described more fully hereinafter) fixed upon an adjustable frame or column 19 mounted in the base 7. The work regulating wheel 18 may be driven preferably, at a relatively slow rate, directly from a separate source of power, or from the same source of power which drives the grinding wheel, by means of a shaft 20. bevel gears 21, shafts 22 and 23 connected by telescoping shaft 24 and the universal connections 25, spiral gears 26 and spindle 27 which is operatively connected with the regulating wheel 18.

The driving spindle 27 is mounted in suitable ball bearings 28 separated by a spacer 29, as shown in Fig. 2. The ball bearings 28 are mounted within a hollow stationary cantilever supporting member 30 shrunk in a cylindrical opening in an adjustable frame 31 suitably carried on the column '19, a portion of the supporting member bein ed toward the right, as viewed in igure 2, and hence being opposed to the grinding wheel. The member 30 will be seen to be tubular and hence of great rigidity; also and preferably the right-hand or extended portion thereof is conveniently and preferably of lesser diameter than the left-hand portion thereof which is fitted within the frame 31, this difference in diameter of these two portions resulting in theprovision of a shoulder 35. A sleeve or sleeve-like bearing 33 is mounted for rotation upon and relative to a portion (the right-hand portion, as seen in Figure 2) of hollow cantilever supporting member 30 which is radially op posed to the grinding wheel. The member 33 has an inclined or tapered portion 34 adjacent its left-hand end (as seen in Figure 1) overlapping the shoulder 35 on the supporting member 30. An appropriate closure, such as packing 36, is provided between the left-hand end. of the sleeve member or bearing 33 and the shoulder 35 of the supporting member 30.

Suitable driving connections are provided between the spindle 27 and the sleeve-like bearing 33 such, for example, as an interior gear or spline 37 meshing in slots in the spindle 27 and secured by means of a pin 38 to a A portion 39 of the sleeve or bearing 33 which projects beyond the outer end of the cantilever supporting member 30. The packing 36 is held in contact with the left-hand en of the bearing 33 and the shoulder 35 of the supporting member 30, which in effect is integral with the frame 31, by means of a spring 40 surrounding the end of the drive shaft 27 and held against the gear 37 by means of a spanner nut 41 and a lock nut 42 on the threaded end portion of the spindle 27. The spring 40 urges the sleeve-like bearing member 33 in a direction toward the left, as viewed in Figure 2, and thus insures that the packing 36 1s yieldingly held in dependable sealing relation with respect to the shoulder 35 and the member 33. A closure, such as a threaded cap 43, is screwed upon the outer surface of the projecting ortion 39 of the sleevelike bearing 33 and has a screw threaded extension 44.

Annular ribs 45 projecting inwardly from the drum 46 of the work regulating wheel 18 are adapted for slidably mounting the wheel 18 upon and around the sleeve-like bearing 33, so as to be removable endwise thereof. An adjustable device is provided for positioning and holdin the work regulating wheel 18 upon the aring 33 for rotation therewith. Thus, an annular inwardly tapering sleeve 47 is slidably mounted upon the bearing 33 and may be moved inwardly (to the left, as viewed in Figure 2) to posiextend annular ribs 45 of the wheel drum 46 to decap 48 and an adjusting nut 49 on the screwthreaded portion 44 of the closure ,43.

I have found that the spring presses the bearing 33 and the packing 36 against the shoulder 35 of the cantilever supporting member 30 to maintain a connection therewith which together with the closure v43 at the other end of the bearing effectively prevents access of foreign matter, such as grinding liquid and dirt upon the bearing surface. Together with these wheel mounting of the invention is of simple construction" and easily manufactured, and is sufliciently rigid to satisfy the most exacting grinding requirements,

It will thus be seen that there has been provided in this invention a construction in which the several objects hereinbefore noted, as well as many thorou hly practical advantages, are successive y achieved. The mounting of the regulating wheel in particular is extremely rapid and is capable of withstanding enormous strains. the wheel 18 may be readily and conveniently put in place, removed, or replaced by another wheel. The tapered portion 34 of the sleeve-like bearing 33 and the left-hand and tapered end of the sleeve 47 coact with the pendably center the wheel 18 with respect to the axis of the rotating bearing 33 and the clamping action of the end cap 48 and nut 49 insure the dependable maintenance of the my wheel 18 in assembled relation with respect to the bearing 33 with which it rotates. The wheel 18 can be readily removed by simply removing the nut 49 and the end cap 48 whereupon the sleeve 47 and the drum 46 with the wheel mounted thereon can be readily slid oil of the sleeve bearing 33 all without having to disturb the relation of the bearing 33 with respect to the cantilever supporting arm 30, about whichthe bearing sleeve member 33 rotates, or without disturbing the driving connection between the drive shaft 27 and the bearing member 33. Similarly, also, tht packing 36 need not be disturbed during the removal or mounting of the wheel 18, the spring 40, moreover, acting, as above noted, to dependably maintain the desired sealing action in which the packing 36 takes part.

Thus, it will be seen that many thoroughly practical advantages are achieved and that the construction is well adapted to -meet the varying conditions of hard practical use. It is possible, for example, to remove or change the wheel or to mountit in position very quickly, without requiring undue skill and without interfering with any of the driving or bearing mountings and connections.

As man possible embodiments may be made of t e above invention and as many advantages the Moreover,

changes might be made in the embodiment 'above set forth, it'is to be understood that all matter hereinbefore set forth or shown 1n the accompanying drawing is to be interpreted as illustrative and not in a limiting sense. I

Having thus described my invention, what I claim as new and desire to secure by Letters'Patent is: v I

1, In a grinding .machine including a grinding wheel, a regulating wheel peripherally opposed to the grinding wheel, and means for holding work between said wheels, means mounting said regulating wheel comprising, in combination, a bearing Within the regulating wheel, and a rigid support within said regulating which said bearing is rotatably mounted, said support being positioned in radial 0pposition to said grinding wheel, whereby the thrust vof the grinding wheel transmitted through the work to the regulating wheel is received by said support directly and radially through said bearing.

2. In a grinding machine including. a grinding wheel, a regulating wheel opposed to the grinding wheel, one of said wheels being operative by way of its-peripheral I face, and means for holding Work between port dlrectly and radially through said bearing. a

3. In a grinding machine including a grinding wheel, a regulating wheel peripherally opposed to the grinding wheel, and means for holding work between said wheels, means mounting said regulating wheel comprising, in combination, a rigid cantilever supporting member having an end portion positioned in radial opposition to said grinding wheel, and a bearing upon which the regulating wheel is removably mounted, said bearing being rotatabl supported upon said end portion of said cantilever supporting omember,-whereby the thrust of the grinding wheel transmitted through the work to the regulating wheel is received by said cantilever supporting member directly and radially through said bearmg. i

4. In a grinding machine including a grinding wheel, a regulating wheel peripheraly opposed to the grinding wheel, and means for holdingwork between said wheels, means mounting said regulating wheel comprising, in combination, a rigid cantilever supporting member having an end portion wheel and upon IOU - idly positioned in radial opposition to said grinding wheel, a bearing upon which the regulat ing wheel is removably mounted, said bearing being rotatably supported upon said end portion of said cantilever supporting member, whereby the thrust of the grinding wheel transmitted through the work to the regulating wheel is received by said cantilever supporting member directly and radially through said bearing, and means mounting said cantilever supporting member to swing about an axis transverse to the axis of rotation of said regulating wheel and extending substantially through the center of said regulating wheel.

5. In a grinding machine, in combination, a base, a cantilever supporting member rigsecured to said base, a bearing mounted for rotation uponand about said cantilever supporting member, an abrasive wheel removably mounted upon said bearing and adapted to rotate therewith, and means for rotating said wheel and said bearing relative to said supporting member.

6. In a grinding machine, in combination, a stationary supporting member, a bearing rotatably mounted thereon, means removably holding said bearing in position upon said supporting member vent endwise movement thereof, an abrasive wheel surrounding and adjustably fixed on said bearing and removable endwise therefrom, and means for rotating said wheel and said bearing relative to said supporting member.

7. In a grinding machine, in combination, a rigid cantilever supporting member, a bearing rotatably mounted thereon, an abrasive wheel surrounding and fixed upon said bearing and removable endwise therefrom, means for sealing the ends of said bearing to prevent the entrance of grinding liquid and dirt to the bearing surfaces, and means for rotating said wheel and said bearing relative to said supporting member.

8. In a grinding machine, in combination, a cantilever supporting member, a bearing rotatably mounted thereon, an abrasive wheel mounted upon said bearing and removable endwise therefrom, and means for rotating said bearing relative to said supporting member to rotate said wheel.

9. In a grinding machine, in combination, a rigid supporting member, a bearing rotatably mounted upon said supporting member, an abrasive wheel fixed upon said bearing, means for rotating said bearing relative to said supporting member to rotate said wheel, packing between said supporting member and one end of said bearing, means for maintaining said packing in contact with said supporting member and said bearing during rotation of said wheel to prevent entrance of grlnding liquid and dirt to the bearing surof said supporting member,

and adapted to prefaces, and a closure for the other end of said bearing.

10. n a grinding machine, in combination, a rigid supporting member, a bearing rotatably mounted upon said supporting member, an abrasive wheel fixed .upon said bearing, and a driving shaft passing through said supporting member and connected to drive said wheel.

11. In a grinding machine, in combination, a rigid hollow cylindrical cantilever supporting member, a bearing rotatably mounted upon and projecting beyond the outer end an abrasive wheel mounted upon said bearing for rotation therewith, a drive spindle rotatably mounted within said supporting member, and means connecting the end of said spindle with the projecting portion of saidbearing to rotate said bearing and said wheel.

12. In a grinding machine, in combination, a stationary hollow supporting member, a bearing rotatably mounted thereon, an abrasive wheel removably mounted upon the exterior of said bearing, and a rotatable spindle mounted within said hollow supporting member and connected externally thereof with said wheel to rotate said wheel.

13. In a grinding machine, in combination, a cantilever supporting member, a bearing mountedthereon for rotation relative thereto and having an inclined portion on its outer surface, an abrasive wheel mounted upon said bearing, an annular tapered sleeve slidably mounted upon said bearing, an adjustable cap abutting said sleeve and adapted to move the same along the outer surface of said bearing to wedge against said wheel and thereby position and hold said wheel firmly on said inclined portion of the bearing, and means for rotating said wheel.

14. In a grinding-machine in combination, a stationary hollow cylindrical cantilever supporting member, a caring mounted for rotation thereon, acking between one' end of said bearing and said supporting member, an abrasive wheel mounted upon said bearing for rotation therewith, a drive spindle rotatably mounted within said supporting member, a driving connection between said spindle and said bearing, and a closure for the other end of said bearin 15. In a grinding mac ine, in combination, a cantilever supporting member, a bearing mounted for rotation thereof, packing between one end of the bearing and said suporting member, means for forcing said bearing toward said packing to maintain firm contact of said packing and to prevent the entrance of grinding liquid or dirt to the bearing surface, an abrasive wheel mounted upon said bearing for rotation therewith, means for rotating said wheel. and a closure for the other end of said bearing.

16. In a grinding machine, in combination,

a cantilever supporting member, a bearing mounted for rotation thereon, packing between one end of said bearing and said supporting member, a cap secured upon and closing the other end of said bearing, means w1thin said cap urging said bearing toward said packing, an abrasive wheel mounted upon the exterior of said bearing, and means exterior of said cap for removably holding said wheel in position upon said bearing.

17 In a grinding machine, in combination, a frame having a hollow portion and bearing means projecting therefrom, a shaft rotatably mounted in said hollow portion and extending into said projecting means, a sleevelike member rotatably supported by said projecting bearing means and carrying an abrasive wheel, and means forming a driving connection between the outer end of said shaft and the outer end of said, sleeve-like member.

18. In a grinding machine, in combination, a frame having a hollow portion and bearing means projecting therefrom, a shaft rotatably mounted in said hollow portion and extending into said projecting means, a sleeve-like member rotatably supported by said projecting bearing means and carrying an abrasive wheel, means forming a driving connection between the outer end of said shaft and the outer end of said sleeve-like member, and means enclosing said driving connection and adapted to prevent entry of foreign matter into said sleeve-like member.

19. In a grinding machine, in combination, a frame having a hollow portion and bearing means projecting therefrom, a shaft rotatably mounted in said hollow portion and extending into said projecting means, a sleeve-like member rotatably supported by said projecting bearing means and carrying an abrasive wheel, means urging said sleevelike member in, a direction toward said frame, packing material interposed between said sleeve-like member and said frame, and means forming a driving connection between said sleeve-like member and said shaft and adapted to permit movement of said sleevelike member toward said frame.-

20. In a grinding machine, in combination, a frame having a hollow portion and bearing means projecting therefrom, a shaft rotatably mounted in said hollow portion and extending into said projecting means, a sleevelike member rotatably supported by said projecting bearing means and carrying an abrasive wheel, means urging said sleeve-like member in a direction toward said frame, packing material interposed between said sleeve-like member and said frame, means forming a driving connection between said sleeve-like member and said shaft and adapted to permit movement of said sleeve-like member toward said frame, and means for substantially sealing the outer end of said sleeve-like member against the entry thereinto of foreign matter.

21. In a grinding machine, in combination, a frame having a hollow portion and hollow bearing means projecting away therefrom, a shaft extending into said hollow bearing means and having a bearing support in said hollow portion, a sleeve-like member rotatably supported by said projecting bearing means, an abrasive wheel having a drum adapted to be received upon said sleeve-like member, means forming a driving connection between said sleeve-like member and said shaft, and means including a cap-like member received over the end of said sleevelike member for substantially closing the latter and for securing said drum thereto.

22. In a grinding machine, in combination, a frame having a tubular member mounted therein, said tubular member projecting away from said frame'and the projecting portion thereof being of lesser diameter, thereby to form a shoulder, a shaft rotatably supported by said tubular member and projecting into said projecting portion thereof, an abrasive wheel mounted upon a sleeve-like bearing member, the latter being rotatably supported by said projecting portion of said tubular member, packing material interposed between said sleeve-like member and said shoulder, means for urging said sleeve-like member in a direction toward said shoulder, and means forming a driving connection between said shaft and said sleevelike member.

23. In a grinding machine, in combination, a frame having a tubular member mounted therein, said tubular member projecting away from said frame and the projecting portion thereof being of lesser diameter, thereby to form a shoulder, a shaft rotatably supported by said tubular member and projecting into said projecting portion thereof, an abrasive wheel mounted upon a sleeve-like bearing member, the latter being rotatably supported by said projecting portion of said tubular member, packing material interposed between said sleeve-like member and said shoulderf" means for urging said sleeve-like member in of July, 1925.

ERNEST R. SEWVARD. 

